1. Technical Field
The present invention relates to a series of novel P-chiral monophosphorus ligands derived from a dihydrobenzo[1,3]oxaphosphole framework and their metal complexes as catalysts for applications in cross-coupling reaction. More particularly, the present invention relates to these phosphine ligands and their related catalysts for transition metal catalyzed cross-coupling reactions including carbon-carbon bond forming reactions and C—X cross-coupling reactions.
2. Background Information
Metal-catalyzed cross-coupling has become one of the most important transformations in organic chemistry. A. de Meijere, F. Diederich, Eds. Metal-Catalyzed Cross-Coupling Reactions, Vol. 2: Wiley-VCH, Weinheim, 2004. J.-P. Corbet, G. Mignani, Chem. Rev. 2006, 106, 2651. Development of efficient chiral or nonchiral ligands for metal-catalyzed cross-coupling has gained particular attention in the latest twenty years. As ligands have played essential roles during each step of the catalytic cycle including oxidative addition, transmetallation, and reductive elimination, the steric and electronic properties of ligand can greatly influence the rate, regioselectivity, and stereoselectivity of the cross-coupling reaction. Recent advances pioneered by Buchwald (T. E. Barder, S. D. Walker, J. R. Martinelli, S. L. Buchwald, J. Am. Chem. Soc. 2005, 127, 4685; S. D. Walker, T. E. Barder, J. R. Martinelli, S. L. Buchwald, Angew. Chem., Int. Ed. 2004, 43, 1871; K. Billingsley, S. L. Buchwald, J. Am. Chem. Soc. 2007, 129, 3358; S. L. Buchwald, B. P. Fors, D. S. Surry, WO2009/076622), Hartwig (J. F. Hartwig, Q. Shelby, N. Kataoka, WO 2002/011883; M. Driver, J. F. Hartwig, J. Am. Chem. Soc. 1996, 118, 7217), Fu (M. R. Netherton, C. Dai, K. Neuschuta, G. C. Fu, J. Am. Chem. Soc. 2001, 123, 10099; J. H. Kirchoff, M. R. Netherton, I. D. Hills, G. C. Fu, J. Am. Chem. Soc. 2002, 124, 13662), and Beller et al (A. Zapf, A, Ahrentraut, M. Beller Angew. Chem., Int. Ed. 2000, 39, 4153; A. Ahrentraut, A. Zapf, M. Beller, Adv. Synth. Catal. 2002, 344, 209; A. Zapf, R. Jackstell, F. Rataboul, T. Riermeier, A. Monsees, C. Fuhrmann, N. Shaikh, U. Dingerdissen, M. Beller, Chem. Comm. 2004, 38) have led to the development of many efficient ligands for cross-coupling reactions including carbon-carbon bond forming reactions and C—X cross-coupling reactions. Some efficient ligands are summarized below:

The Suzuki-Miyaura coupling has become one of most useful method for formation of carbon-carbon bonds and has been used in numerous synthetic ventures. (N. Miyaura, Topics in Current Chem. 2002, 219, 11; A. Suzuki, Organomet. Chem. 1999, 576, 147). Despite the recent advances on this reaction, the Suzuki-Miyaura coupling of sterically hindered substrates and further decrease of the catalyst loading remain great challenges. Development of new ligands for Suzuki-Miyaura coupling reaction remains imperative to further increase its efficiency and expand its substrate scope.